Alleviated Temperature but Intensified Water Constraints on Global Vegetation Productivity

Global variations in vegetation productivity are intricately linked to climatic fluctuations, yet the specific impacts of climate change on these constraints remain uncertain. We employed the extreme gradient-boosting model within the Shapley framework of additive explanations to delineate temperature, water, and solar radiation constraints on productivity and traced their temporal evolution from 1980 to 2022. The results revealed a distinctive spatiotemporal pattern of the climatic limitations: temperature emerged as the primary constraint early during the growing season in most temperate, boreal, and polar regions, and temperature and radiation jointly limited productivity in these regions during the intermediate and late growing season; water predominantly constrained productivity mainly in arid areas, whereas equatorial rainforests were primarily limited by radiation. Furthermore, our analysis indicated a moderated temperature constraint but an intensified water constraint on global productivity.